Low-foaming alkaline, hypochlorite cleaner

Abstract

Cleaning formulations suitable for cleaning equipment which circulates food products, such as dairy products, in place. The formulations are alkaline compositions containing a source of available chlorine (suitably hypochlorite) and including a mixture of surfactants one of which is a C 4 -C 6 alkylated diphenyloxide sulfonate and the other of which is a nonionic surfactant which is stable in the formulation within certain concentration ranges and which acts to suppress foaming.

What is claimed is: 
     
       1. An aqueous alkaline chlorinated cleaning formulation comprising: (a) an alkaline hydroxide in an amount equivalent to about 5% - 15% sodium hydroxide;   (b) a component providing available chlorine at a level of between about 1% and about 5% available chlorine;   (c) between about 0.1% and about 2% of a surfactant mixture comprising (i) a sulfonate surfactant selected from the group consisting of alkyl diphenyloxide sulfonates, having one or two alkyl groups and two sulfonate groups, the alkyl groups being linear or branched C 4  -C 8  alkyl groups, and (ii) a nonionic surfactant selected from the group consisting of poly(oxyethylene)/poly(oxypropylene) block copolymers and polyethoxylated/polypropoxylated aliphatic alcohols; and   (d) 0 to about 15% of a water softening agent stable to the other components of the formulation, said sulfonate and nonionic surfactants being present in a ratio of between about 2.5:1 and 3.5:1 and said nonionic surfactant selected to provide a substantially clear solution at about 120° F. when combined with the remaining ingredients of the formulation.   
     
     
       2. A formulation as in claim 1 wherein the sulfonate surfactant is a dialkyl diphenyloxide disulfonate. 
     
     
       3. A formulation as in claim 2 wherein the alkyl groups on the sulfonate surfactant are linear groups having an average of about six carbon atoms. 
     
     
       4. A formulation as in claim 1 wherein the water softening agent is selected from the group consisting of silicate, phosphate, phosphonate and polyacrylate softening agents and mixtures thereof. 
     
     
       5. A formulation as in claim 4 wherein the water softening agent is an alkali polyacrylate salt. 
     
     
       6. A formulation as in claim 1 wherein the alkali hydroxide is sodium or potassium hydroxide or a mixture thereof. 
     
     
       7. A formulation as in claim 1 wherein the available chlorine providing component is sodium or potassium hypochlorite or a mixture thereof. 
     
     
       8. A formulation as in claim 1 wherein the nonionic surfactant is a polyethoxylated/polypropoxylated C 4  -C 10  linear or branched aliphatic alcohol. 
     
     
       9. A formulation as in claim 1 wherein the nonionic surfactant has a cloud point (1% aqueous solution) of about 24°-25° C. 
     
     
       10. A formulation as in claim 9 wherein the nonionic surfactant gives a dynamic foam height (0.1% aqueous solution, 400 ml/min, 49° C.) of 5 mm or less. 
     
     
       11. A formulation as in claim 9 wherein the nonionic surfactant has a HLB value of about 7. 
     
     
       12. A method of cleaning-in-place equipment used to circulate food products comprising: (a) providing a formulation as in claim 1;   (b) diluting said formulation with water at a ratio of between about 1:320 and 1:40; and   (c) circulating the diluted formulation through the said equipment to be cleaned at a temperature of above 90° F.   
     
     
       13. A method as in claim 12 wherein the diluted formulation temperature is between about 90° F. and 165° F. when circulated through the equipment. 
     
     
       14. A method as in claim 12 wherein the equipment to be cleaned is milk handling equipment.